1. Technical Field
The disclosure relates to a lens and a light source module with the lens.
2. Discussion of Related Art
Light emitting diodes (LEDs) with many advantages, such as high luminosity, low operational voltage, low power consumption, compatibility with integrated circuits, faster switching, long term reliability, and environmental friendliness have promoted their wide use as a lighting source.
Conventional tubular light source module includes a substrate and a plurality of LEDs arranged on the substrate in line. However, the LED generally generates a small spot with a radiation angle less than 120 degrees. The intensity of light emitted by the LEDs is concentrated, wherein the light intensity dramatically decreases when the radiation angle exceeds 120 degrees. The distribution of light emission of the conventional tubular light source is uneven when the LEDs are arranged sparsely. Therefore, it needs a plurality of LEDs arranged in line closely in order to achieve even light distribution. However, use of so many LEDs is costly.
Therefore, what is needed is a lens and a light source module with the lens which can overcome the described limitations.